Blow molding machines work by using heat, molds, and air pressure to shape plastic material into hollow products such as bottles and jugs. In the extrusion blow molding process, plastic raw material in the form of pellets is fed into a hopper, then flows into the barrel to be heated and melted by heating elements and the rotation of the screw. The molten material is then extruded through a die in the form of a plastic tube called a parison. After that, the mold closes and compressed air is injected into the parison, causing the material to expand to fill the mold cavity. This process produces bottles or jugs with shapes that match the predetermined design.

Once the forming process is complete, the product is cooled until the plastic hardens and can be removed from the mold. The next steps include trimming excess material, inspecting the shape, and checking product quality before packaging or distribution. In the production of bottles and jugs, several factors—such as heating temperature, air pressure, cooling time, and wall thickness—must be carefully controlled to ensure the containers have precise shapes and are leak-resistant. Proper parameter settings also help reduce defective products and improve the efficiency of raw material usage.

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